Commit 8f0dfc34 authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Ingo Molnar

sched: Provide iowait counters

For counting how long an application has been waiting for
(disk) IO, there currently is only the HZ sample driven
information available, while for all other counters in this
class, a high resolution version is available via
CONFIG_SCHEDSTATS.

In order to make an improved bootchart tool possible, we also
need a higher resolution version of the iowait time.

This patch below adds this scheduler statistic to the kernel.
Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4A64B813.1080506@linux.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent f14eff1c
...@@ -1111,6 +1111,8 @@ struct sched_entity { ...@@ -1111,6 +1111,8 @@ struct sched_entity {
u64 wait_max; u64 wait_max;
u64 wait_count; u64 wait_count;
u64 wait_sum; u64 wait_sum;
u64 iowait_count;
u64 iowait_sum;
u64 sleep_start; u64 sleep_start;
u64 sleep_max; u64 sleep_max;
...@@ -1231,6 +1233,8 @@ struct task_struct { ...@@ -1231,6 +1233,8 @@ struct task_struct {
unsigned did_exec:1; unsigned did_exec:1;
unsigned in_execve:1; /* Tell the LSMs that the process is doing an unsigned in_execve:1; /* Tell the LSMs that the process is doing an
* execve */ * execve */
unsigned in_iowait:1;
/* Revert to default priority/policy when forking */ /* Revert to default priority/policy when forking */
unsigned sched_reset_on_fork:1; unsigned sched_reset_on_fork:1;
......
...@@ -6754,7 +6754,9 @@ void __sched io_schedule(void) ...@@ -6754,7 +6754,9 @@ void __sched io_schedule(void)
delayacct_blkio_start(); delayacct_blkio_start();
atomic_inc(&rq->nr_iowait); atomic_inc(&rq->nr_iowait);
current->in_iowait = 1;
schedule(); schedule();
current->in_iowait = 0;
atomic_dec(&rq->nr_iowait); atomic_dec(&rq->nr_iowait);
delayacct_blkio_end(); delayacct_blkio_end();
} }
...@@ -6767,7 +6769,9 @@ long __sched io_schedule_timeout(long timeout) ...@@ -6767,7 +6769,9 @@ long __sched io_schedule_timeout(long timeout)
delayacct_blkio_start(); delayacct_blkio_start();
atomic_inc(&rq->nr_iowait); atomic_inc(&rq->nr_iowait);
current->in_iowait = 1;
ret = schedule_timeout(timeout); ret = schedule_timeout(timeout);
current->in_iowait = 0;
atomic_dec(&rq->nr_iowait); atomic_dec(&rq->nr_iowait);
delayacct_blkio_end(); delayacct_blkio_end();
return ret; return ret;
......
...@@ -409,6 +409,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) ...@@ -409,6 +409,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
PN(se.wait_max); PN(se.wait_max);
PN(se.wait_sum); PN(se.wait_sum);
P(se.wait_count); P(se.wait_count);
PN(se.iowait_sum);
P(se.iowait_count);
P(sched_info.bkl_count); P(sched_info.bkl_count);
P(se.nr_migrations); P(se.nr_migrations);
P(se.nr_migrations_cold); P(se.nr_migrations_cold);
...@@ -479,6 +481,8 @@ void proc_sched_set_task(struct task_struct *p) ...@@ -479,6 +481,8 @@ void proc_sched_set_task(struct task_struct *p)
p->se.wait_max = 0; p->se.wait_max = 0;
p->se.wait_sum = 0; p->se.wait_sum = 0;
p->se.wait_count = 0; p->se.wait_count = 0;
p->se.iowait_sum = 0;
p->se.iowait_count = 0;
p->se.sleep_max = 0; p->se.sleep_max = 0;
p->se.sum_sleep_runtime = 0; p->se.sum_sleep_runtime = 0;
p->se.block_max = 0; p->se.block_max = 0;
......
...@@ -652,6 +652,11 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) ...@@ -652,6 +652,11 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->sum_sleep_runtime += delta; se->sum_sleep_runtime += delta;
if (tsk) { if (tsk) {
if (tsk->in_iowait) {
se->iowait_sum += delta;
se->iowait_count++;
}
/* /*
* Blocking time is in units of nanosecs, so shift by * Blocking time is in units of nanosecs, so shift by
* 20 to get a milliseconds-range estimation of the * 20 to get a milliseconds-range estimation of the
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment